Who are the best genetic sources in Holsteins?

Submitted by admin on Mon, 02/01/2010 - 10:12

Hoard's Dairyman:

Who are the best genetic sources in Holsteins?

Date:

Mon, 02/01/2010

For nearly four decades, Penn State's Larry Specht has been evaluating which farms and sires have been the best contributors to genetic progress in the Holstein breed. For his efforts, Specht was named a pioneer by the National Dairy Shrine. The Sire-Son Report ranks a bull based on the average of his son's predicted transmitting ability (PTA) for 11 traits. "The report has long been a valuable educational tool to demonstrate that the bulls with the best daughters are generally those with the best sons," says Penn State's Chad Dechow. "Thought of another way, bulls with the best daughters are also those that are likely to have the best granddaughters," says Dechow. "This seems pretty logical to us now, thanks in large part to Dr. Specht's work, but hasn't always been thought to be the case. There are occasionally those bulls that do not fit the mold and his lists help to identify them."

The Prefix Report is based on a similar concept. "A bull's registration name most often begins with the prefix of the farm that bred him," notes Dechow. "This allows us to summarize the performance of a herd's bulls that have gone to stud. The report has been a valuable tool for buyers of elite genetic stock," says Dechow. "It helps them determine those herds that provide them with the best odds of purchasing a bull or cow that will go on to have outstanding genetic merit.

A recent addition to Specht's work is the Bull-Mother Report. The report is identical to the Sire-Son Report, except that it tracks how well a cow's sons perform once they enter stud.

Only sires and herds with at least 20 sons in A.I. during the past 25 years are considered. Cows are required to have 10 sons to be listed. Genomic selection has added a new wrinkle to genetic selection programs. Currently, only bulls with a progeny test are considered for the lists. However, plans are underway to expand the list to include bulls with genomic-only information.